Due to higher national income, the growth of both cars and motor bicycles has been very rapid in recent years. As a result, the volume of traffic is increasing day by day.
Traffic has become a subject to be concerned about by the general public.
In the meantime, the possibility of driving at night has increased. Therefore, the current volume of traffic is at high level almost 24 hours a day. When driving at night, it is necessary to turn on the headlamps, which is explicitly set out by law.
According to our experiences in respect to the driving at night, although it needs to change the headlamp luminosity subject to the road conditions from time to time, it is often heard that the driver's eyes get dazzled by the strong light coming from the car in the opposite direction, especially on the road without a traffic island. Maybe such a strong light is beyond control, not intentionally caused by the driver in the opposite direction, but some traffic accidents have happened due to such a situation.
Besides, when driving on a road with a considerable amount of curves, the driver must frequently alternate distance light with dim light all the way. In this case the driver may become exhausted when he finishes his run.